Siege of Naissos (27 BC)

The Siege of Naissos occurred in 27 BC when the Roman general Marcus Licinius Crassus, in command of Legio VIII Macedonica, captured the city of Naissos in western Thrace from the Celtic Scordisci. The Romans were able to easily conquer the settlement, with their legionaries easily slaughtering the Celtic tribesmen and conquering the western quarter of Thrace; the Scordisci were forced to retreat into their Pannonian homeland in the north.

Background
In 30 BC, Julius Caesar's adoptive heir Octavian succeeded in defeating his last remaining Roman rival for power, Mark Antony, after forcing him to flee to his lover Queen Cleopatra in Egypt, where they committed suicide rather than be captured. Three years later, the Roman Senate conferred upon Octavian the title Princeps ("Prince") and the regnal name "Augustus", and he became the first ruler of the Roman Empire. His empire stretched from Gaul and Hispania in the west to the Balkans, Asia Minor, the Levant, and Aegyptus in the east, and he also commanded the tacit loyalty of several client kingdoms which paid him tribute in exchange for military protection from rivals. The Roman Empire grew very wealthy due to its vast annual income through taxation and trade, and it was able to pay for the maintenance of several legions across the vast empire.

In the autumn of 27 BC, Emperor Augustus received a plea for assistance by King Cotys II of the Odrysian Kingdom in Thrace, now Bulgaria. Cotys was threatened by the expansion of the Celtic Scordisci, who had migrated south from Pannonia and settled in western Thrace at the town of Naissos, and planned to expand further into the Thracian heartland. Augustus honored his treaty with Thrace by dispatching the 1,500-strong Legio VIII Macedonica under Marcus Licinius Crassus from Thessalonica in Macedonia to invade the Scordisci lands and conquer western Thrace and Pannonia for Rome.

Siege
The Scordisci king Gaisio and his army were originally encamped at Naissos, but they later withdrew north to Singidun (now Belgrade, Serbia) upon hearing the news of the approach of a Roman legion. The Romans therefore faced a 720-strong garrison under Lucterios, a minor chief of the tribe. In the ensuing battle, the Roman legionaries advanced on the unarmored Celtic tribesmen, who attempted to shower arrows and javelins onto the Romans. However, the Roman cavalry succeeded in charging and massacring the Celtic javelinmen, while the Roman legionaries entered into a fierce melee with the Celtic spearmen. In the ensuing battle, the Romans were able to kill or capture the vast majority of the Scordisci warriors, taking only 71 losses in the process.

Aftermath
The capture of Naissos, while easy, gave the legion more combat experience, and the legion would later move north from Naissos to attack Singidun, the Scordisci capital. The Romans initiated the rebuilding of Naissos as a Roman town, and Legio IX Illyrica was later deployed to the town to quell rising unrest caused by the rebellious Scordisci locals. Over the years, the presence of Roman cultural buildings led to the assimilation of the locals as Romans.